Disposable tray

ABSTRACT

A light weight serving tray of inexpensive construction is suited particularly for disposable use. The tray is fabricated from a single sheet of material such as corrugated cardboard. Selected regions of the tray are scored and compressably deformed in a manner which insures that the peripheral margin of the tray will assume and maintain its upstanding, rail-like configuration.

United States Patent -1 1 Schneider et a1.

1 1 DISPOSABLE TRAY [76] Inventors: David Schneider, 10 Peachtree Rd.,

Lexington, Mass. 02173; George Shumrak, 17 Fox Hill Dr., Natick, Mass.01760 [22] Filed: Oct. 29, 1971 [21] Appl. No.: 193,620

[52] US. Cl 229/2.5, 229/DIG. 4, 229/DIG. 2 [51] Int. Cl B6511 l/34,B65d 1/44 [58] Field of Search 229/2.5, 3.1, DIG. 2, DIG. 4

[56] References Cited UNITED STATES PATENTS 3,401,863 9/1968 Earl229/2.5 1,748,865 2/1930 Chaplin 229/2.5 2,832,522 4/1958 Schlanger229/2.5

[111 3,792,809 [451 Feb. 19, 1974 Kavanaugh 229/DIG. 2

2,324,757 7/1943 Botley 229/DIG. 2 2,997,927 8/1961 Carson 229/2.5 X3,122,300 2/1964 La Bombard.. 229/DIG. 4 3,659,772 5/1972 Dorsey229/DIG. 4

Primary Examiner-Davis T. Moorhead Attorney, Agent, or Firm-Wolf,Greenfield & Sacks 5 Claims, 9 Drawing Figures PAIENIEB FEB 1 9 m4 sum 2BF 2 FIG. 5

DISPOSABLE TRAY BACKGROUND OF THE INVENTION This invention relates toserving trays of the type used widely in hospitals and otherinstitutions, and in cafeterias, commercial airplanes and other placeswhere a large number of people are to be'fed in a rela tively shorttime. It has been common practice, for a long time, to serve the food ontrays of rigid, permanent construction such as plastic, metal or othersimilar durable material adapted for repetitive use over an extendedperiod of time.'Although these serving trays have, for the most part,proved satisfactory, their use has not been entirely free ofdifficulties. For example, because these trays are used repeatedly,storage and handling facilities must be provided. Additionally, in orderto maintain the trays in a sanitary, hygienic condition, they must bewashed thoroughly after each use. In some instances, this requiresspecial washing machines suited particularly for this purpose. Whenusing conventional serving trays, it sometimes may be desirable to placedoilies or other coverings on the trays to present a more pleasingappearance to the person being served. Furthermore, these permanentserving trays require a somewhat cumbersome manufacturing technique inthat they must be molded or stamped and then finished finally to removeall flash or sharp edges. In contrast, the serving trays of thisinvention may be fabricated by an extremely simple technique which issuited particularly for high volume production. Unlike other previouslyproposed disposable trays which have raw exposed edges and non-uniformappearance, the instant invention has a neatly rolled rim and evenlyrounded corners.

SUMMARY OF THE INVENTION The tray is formed from flat sheet stock ofinexpensive, light weight material such as corrugated cardboard.Although corrugated cardboard is suited particularly for the tray othermaterials may be employed such as those having light weight cellularstructures, such as foam plastics and the like. As used herein, the termcellular construction is intended to mean any such material having amulti-cell configuration and displaying the requisite deformablecharacteristics.

The tray includes the usual flat surface and an upwardly bent outermargin which defines a rim fully about the tray.

One of the primary features of the invention is the manner in which therim is maintained in its upwardly extending configuration after the trayhas been cut and formed and has been removed from the forming apparatus.For this purpose, the forming apparatus includes an arrangement forcompressing a narrow region of the flat part of the tray which extendscontinuously along and adjacent the juncture of the flat part with therim. This narrow band is compressed to an extent so that it is deformedpermanently. The permanently deformed band reduces substantially thedegree to which the rim tends to snap back to or assume its originalflat position with respect to the main flat portion of the tray. Themargin of the tray thus is set firmly in its upwardly bentconfiguration. In the preferred form, the corners of the tray rim areprescored on one face in a radial direction, which causes neat pleats toform at the corners when the rim is bent upwardly out of the centralplane of the tray.

Each tray may be coated on its upper surface with a water-resistantcoating and/or a friction material to retard dishes from slipping abouton the tray. Additionally, the tray may be provided with printed matteron either of its surfaces for decoration, to provide games, advertising,or other reading material.

It is among the primary objects of the invention to provide a low costsingle service food tray.

A further object of the invention is to provide a food serving traywhich does not require any associated storing, washing or othercumbersome facilities for handling the trays.

Still another object of the invention is to provide a food serving. traywhich facilitates the serving of food in a sanitary hygienic manner.

Another object of the invention is to provide a tray which may be formedin a single cutting and forming step from a flat sheet of materialand inwhich the peripheral margin of the tray is self-supporting in itsraildefining attitude.

Still another object of the invention is to provide an improved andsimplified method for fabricating serving trays of the type described.

Yet another object of the invention is to provide a single service trayhaving a neat, tailored appearance comparable to that of a reusabletray.

DESCRIPTION OF THE DRAWINGS The foregoing and other objects of theinvention will be understood more fully from the following detaileddescription thereof, with reference to the accompany ing drawingswherein:

FIG. 1 is an illustration of a finished tray made in accordance with theinvention;

FIG. 2 is an enlarged sectional view of the tray taken along sectionline 2-2 of FIG. 1 showing the juncture of the flat portion and therail-like peripheral margin with cross hatching removed;

FIG. 3 is an elevation, in section of the apparatus employed tofabricate the tray with the flat blank sheet inserted ready forfabrication;

FIG. 4 is an illustration of the tray forming apparatus after the blanksheet has been cut and formed;

FIG. 5 is an illustration similar to FIG. 4 but showing a modified dieand punch arrangement to form a rolled edge on the rim about the tray;

FIG. 6 is similar to FIG. 2 but shows the rim formed withthe apparatusof FIG. 5

FIG. 7 is a fragmentary plan view of a tray blank scored but yetunforrned for another embodiment of this invention;

FIG. 8 is a perspective view of one corner of a tray formed from theblank of FIG 7; and

FIG. 9 is a cross sectional view of the tray corner taken along sectionline 9-9 of FIG. 8.

DETAILED DESCRIPTION FIG. 1 shows the finished tray formed from a singleflat sheet of corrugated cardboard having a flat main surface 10 and anupturned peripheral margin 12 which defines a rail-like member. Thetray, formed in accordance with the invention, includes a narrow region14 which surrounds the main surface 10 and is disposed just inwardly ofthe juncture 16 of the margin 12 with the main surface 10. The narrowregion 14 is compressed during formation of the tray to an extentsufficient so that after the compression forces are removed, the region14 will expand only slightly towards its original thickness and willremain permanently deformed to a substantially reduced thickness fromthat of the original sheet. The margin 12 also is deformably compressedduring formation of the tray but to a lesser degree than region 14 sothat its final thickness will be intermediate that of region 14 and themain surface of the tray. I have found that by compressing of the region14 greater than margin 12, the margin of the tray tends to supportitself at an increased angle to the main surface 10 than had beenpreviously obtainable by merely bending over the marginal portion of theoriginal blank.

FIG. 2 suggests some approximate relative dimensions of a tray formed inaccordance with the invention. In this embodiment, the tray may beformed from flat corrugated cardboard sheet stock of A, B, C or E fluteconfiguration and having a burst strength of approximately 200 lbs. persquare inch Mullen test and having an original thickness of between0.145 and 0.165 inches. After formation, the main surface 10 issubstantially uncompressed and is of the same thickness X" as theoriginal stock. The narrow region 14 may be compressed to an extent sothat after removal from the forming apparatus, its thickness Y" isbetween 0.105 and 0.110 inches. A representative relative thickness 2 ofthe rim 12 might be between 0.130 and 0.145 inches. In the illustrativeembodiment where the material is corrugated cardboard greater strengthis derived if the corrugations extend lengthwise of the tray.

FIGS. 3 and 4 show the apparatus employed to fabricate the trays in aone'step operation. The apparatus includes a form punch 18 having arelatively sharp upper peripheral edge 20. The form punch 18 issurrounded by a trimming die 22 having a sharp upper cutting edge 24.The cutting edge 24 of the die 22 is spaced from the periphery of theform punch 18 around the entire punch 18, by an amount corresponding tothe intended width of the tray margin 12. The

cutting edge 24 of the die 22 preferably is coplanar with the uppersurface of theform punch 18 and particularly its edge 20. v

The apparatus of FIGS. 3 and 4 also includes a combined trimming andforming member 26 which has a peripheral, downwardly extending wall 28adapted to fit between the spaced trimming die 22 and punch 18. Thetrimming and forming member 26 is mounted for driven movement withrespect to punch 18 and trimming die 22 along the path suggested byarrow 30. The outer surface of wall 28 forms a trimming face 32 whichcooperates with cutting edge 24 of trimming die 22 to cut a tray fromthe sheetof flat corrugated blank. The inner surface of wall 28 definesa forming die 34 and is dimensioned to provide only slight clearancebetween it and the outer wall surface 36 of punch 18. In the exampledescribed above this clearance may be approximately 0.030 inch. Theinner portion of the trimming and forming member 26 also includes adownwardly extending shoulder 38 which extends 'fully about the innerperiphery of the wall 28.

When forming a tray using the above described apparatus, trimming andforming member 26 is initially spaced from form punch 18 and trimmingdie 22 to permit the blank sheet stock 40 to be inserted between thetwo, as shown in FIG..3. After'sheet 40 hasbeen positioned in thedevice, member 26 is driven downwardly to simultaneously trim theoutline of the tray and sever it from the sheet 40 between trim face 32and trimming die 22. As member 26 continues its downward advancement,the margin 12 of the severed blank is folded downwardly in the narrowspace 42 between die 34 and the outer wall surface 36 of punch 18. Thisaction causes the margin to be formed into the tray rim and alsocompresses margin 12 so that after removal of the finished tray from theapparatus the marginal portion will be of lesser thickness than that ofthe original stock. The lower edge of forming die 34 may be somewhatrounded, as shown at 44 to facilitate smooth engagement of the formingdie with the downwardly extending margin 12. The downward movement ofthe member 26 is continued to cause shoulder 38 to bear firmly againstand thereby form narrow region 14 of the tray. The shoulder 38 isdimensioned with respect to the path of travel of the member 26 and theupper surface of form punch 18 so that region 14 will be subjected to asubstantial compressive force as described above.

After the trimming and forming downward stroke of the member 26 has beencompleted, it is raised to enable the finished tray to be withdrawn.Although the margin or rim 12 tends to expand back to its original flatconfiguration, this tendency is reduced substantially by the addeddeformation of the narrow band 14. Thus, after the formed tray has beenremoved, the angled configuration of the rim 12 with respect to the mainsurface 10 of the tray has a relatively permanent set. One of thefeatures of the foregoing technique is that because of the compressivedeformation of the narrow region 14, rim 12 tends to become set at asteeper angle than if the rim 12 had been simply bent without theincident compression. For example, I have found that by providing thecompressively deformed region in the tray, the angle between the rim l2and main surface 10 may be increased between 8 to 10 from the angleachieved without compressing the region 14. In the preferred form, themargin is set at an angle of approximately FIG. 5 shows one modifiedarrangement for the punch and die which is intended to produce a trayhaving a rolled edge of the type shown in FIG. 6. This tray issubstantially the same as that heretofore described except that the rimedge 50 is rolled. This is particularly desirable when the tray isformed from corrugated cardboard in order to present a smooth upper edgefor the rim by hiding the severed edge of the corrugated cardboard. Asshown in FIG. 5, the die-punch arrangement employed to produce therolled rim is similar to that shown in FIG. 3 except that the form punch18' has a shoulder 52 extending about its periphery. The upper end ofshoulder 52 includes an upwardly extending rib 54 which defines achannel 56 in cooperation with the sidewall 36 of punch 18. Channel 56and rib 54 cooperate with generally complementary surfaces on theunderside of the wall 28'; these surfaces include a downwardlyprojecting finger 58 and a groove 60. The various parts are dimensionedin relation to each other and to the stroke of the die-punch arrangementso that when the punch and die are in the closed position, the extremeedge of the rim will be constrained in the reversely bent configurationshown in FIG. 5. When the die and punch are separated to remove thetray, the

edge of the rim is deformed to define the rolled configuration shown inFIG. 6.

In FIGS. 7, 8 and 9 a preferred embodiment of tray is shown, which has asomewhat more tailored and orderly appearance than the trays of FIGS. 2and 6. The improved configuration is derived from the controlledpleating of the upper layer of the corrugated cardboard as opposed to arandom pleating which results when no special provisions are made tocontrol the pleat formation.

In FIG. 7 a plan view of the blank is suggested. About the corner 70 aplurality of generally radial V-shaped score lines 72 are formed in theupper surface 74 of the corrugated board. The score lines extend fromthe region of the narrow band area 14 to the very periphery of the blankwhen cut, and each of the score lines generally is in the shape of a Vwith the apex 72a at the region l4 and the wider end 72b at theperiphery. The scored region at each corner extends about approximately90 so as substantially to cover the area which is reduced in size whenthe margin 12 of the tray is bent to the inclined position as suggestedin FIGS. 2 and 6.

When the blank is prescored in the manner suggested in FIG. 7 andsubsequently formed by the techniques of FIGS. 3 and 4 or FIG. 5, acontrolled upset of the corrugated occurs rather than pleated folds in arandom pattern at the corners. This is best illustrated in FIGS. 8 and9. In those figures it will be noted that the folds or pleats which areformed extend into the cellular interior of the corrugated, and theupper surface is left with lines 76 defined by the sides 78 and 80 ofthe V-shaped score lines, which are brought together. That is, theportion 82 of the corrugated which lie between the side margins of theV-shaped score lines are bent into the cellular center of the board (thescalloped center ply), and the marginal lines substantially touch oneanother.

The absence of scored lineson the under side of the corrugated causes asomewhat random pattern to be formed by the pleats 84 on the bottomsurface 86 of the tray at the corners, similar to that which is formedon the upper surface in the embodiments of FIGS. 2 and 6. However,because the bottom of the tray is not ordinarily exposed and does notcommand the attention of the upper surface, the uniformity or lack ofuniformity of the pleating on the bottom surface is relativelyunimportant.

In accordance with the preferred method of forming the tray of FIGS.7-9, the flat sheet stock is prescored at the corners before the blankis cut or the tray formedqThus, a secondary step is added to the trayfabricating process which takes place before the steps suggested inFIGS. 3 and 4 or FIG. 5. It will be appreciated that the prescoring ofthe sheet stock may be employed to advantage whether or not the rim isrolled in the fashion of FIG. 6, although the'tray has a more finishedappearance with the rolled rim of FIG. 6.

Some advantage 'in the fabricating technique may also be derived bysetting up the corners and margin of the tray when the stock is heatedby a heated die or premoistened. The pre-moistening of the stock as wellas the preheating may assist in causing the margin to retain the angularconfiguration to a more exacting degree.

Thus, I have described an improved disposable serving tray and atechnique for its production which enables the tray to be formedeconomically without fitting tabs together, cementing corners, etc.Moreover, the foregoing advantages are obtained while providing the traywith a rim which stands upward from the main surface at a substantialand functionally effective angle.

In the foregoing description and in the following claims, terms such asupward and downward are employed merely for ease of explanation. Itshould be noted that while the punch and die configuration has beendescribed with the trimming and forming member 26 being disposed abovethe punch I8, these parts could be reversed.

It should be understood, however that the foregoing description of theinvention is intended merely to be illustrative thereof, and that otherembodiments and modifications may be apparent to those skilled in theart without departing from its spirit.

What is claimed is:

l. A disposable tray formed from a continuous, integral sheet ofcorrugated cardboard with top and bottom layers and an intermediatescalloped layer,

said tray comprising,

a flat base portion defined by the interior regions of said sheet,

the peripheral margin of said tray being bent upwardly at a juncturewith said flat base portion to define an upturned rim fully about saidtray said rim having a peripheral curved portion,

a narrow region of said flat base portion of said tray extending alongand adjacent the juncture of said flat base portion and said rim beingcompressably deformed to a thickness which is less than that of saidflat base portion, said compressed narrow region enabling said rim toremain permanently at a substantial angle to said flat portion,

and pleats in the top layer of said sheet at said curved portion.

2. A tray as defined in claim 1 further comprising: said rim beingformed at its outer region to define a rolled edge.

3. A tray as defined in claim 1 further characterized said rim having aplurality of peripheral curved portions forming corners of said tray,

score lines in the top layer of the sheet at the peripheral margin andextending generally radially out from said juncture in the areas of therim which are curved,

and orderly pleats being formed in the top surface at said areas andextending into the scalloped layer.

4. A tray as defined in claim 3 further characterized by each of thescore lines being generally V-shaped with the apex of the V lying at thejuncture and the open end of the V lying at the edge of the rim.

-5. A disposable tray as defined in claim 1 further characterized by,

said rim being compressedly deformed to a thickness which is less thanthe thickness of said flat base portion but is greater than thethickness of said nar row region.

1. A disposable tray formed from a continuous, integral sheet ofcorrugated cardboard with top and bottom layers and an intermediatescalloped layer, said tray comprising, a flat base portion defined bythe interior regions of said sheet, the peripheral margin of said traybeing bent upwardly at a juncture with said flat base portion to definean upturned rim fully about said tray said rim having a peripheralcurved portion, a narrow region of said flat base portion of said trayextending along and adjacent the juncture of said flat base portion andsaid rim being compressably deformed to a thickness which is less thanthat of said flat base portion, said compressed narrow region enablingsaid rim to remain permanently at a substantial angle to said flatportion, and pleats in the top layer of said sheet at said curvedportion.
 2. A tray as defined in claim 1 further comprising: said rimbeing formed at its outer region to define a rolled edge.
 3. A tray asdefined in claim 1 further characterized by said rim having a pluralityof peripheral curved portions forming corners of said tray, score linesin the top layer of the sheet at the peripheral margin and extendinggenerally radially out from said juncture in the areas of the rim whichare curved, and orderly pleats being formed in the top surface at saidareas and extending into the scalloped layer.
 4. A tray as defined inclaim 3 further characterized by each of the score lines being generallyV-shaped with the apex of the V lying at the juncture and the open endof the V lying at the edge of the rim.
 5. A disposable tray as definedin claim 1 further characterized by, said rim being compressedlydeformed to a thickness which is less than the thickness of said flatbase portion but is greater than the thickness of said narrow region.